Recently, in order to implement a next generation mobile communication, e.g., 5G mobile communication, discussion on highly reliable communication is in progress. An MCS (mission critical service) corresponding to an example of the highly reliable communication requires error free transmission. An M2M communication field also requires the necessity of the highly reliable communication as a method of satisfying real-time for traffic safety, traffic efficiency, efficient industrial communication, and the like. The highly reliable communication can be utilized in various fields such as an application, a medical/emergency response, remote controlling, sensing, and the like sensitive to delay.
According to the MCSs discussed in 3GPP standardization meeting, it is able to expect that there may exist more improvement in End-to-End Latency, Ubiquity, Security, Availability/Reliability compared to legacy UMTS/LTE, and LTE-A/Wi-Fi. The currently proposed commercial radio technologies (e.g., 3GPP LTE, LTE-A) are unable to satisfy the requirements of the MCS in terms of the real time and the reliability. Meanwhile, an evaluation criterion for communication reliability can be defined according to various schemes. For example, the evaluation criterion can be defined by quality of wireless connection that satisfies a level of a specific service, by which the present invention may be non-limited.
In order to implement highly reliable communication for MCSs, it is required to have improvement in a method of sensing and controlling a radio link, a method of controlling dualization of a radio link connection, a method of promptly recovering a radio link connection, a method of managing a security key for safe wireless transmission, authentication, a method of protecting a personal privacy, and the like. To this end, discussion on a method of quickly searching for an available alternative link near a user equipment and managing the link in consideration of power consumption, a method of improving reliability/availability in providing a service via an optimized radio link connection, a method of minimizing service interruption time for a user equipment via quick recovery when a radio link is disconnected, a method of implementing safe communication by preventing intentional radio link damage, and the like is in progress.